Abstract

Background Psychological interventions for postnatal depression can
be beneficial in the short term but their longer-term impact is unknown.

Aims To evaluate the long-term effect on maternal mood of three
psychological treatments in relation to routine primary care.

Method Women with post-partum depression (n=193) were
assigned randomly to one of four conditions: routine primary care,
non-directive counselling, cognitive—behavioural therapy or
psychodynamic therapy. They were assessed immediately after the treatment
phase (at 4.5 months) and at 9, 18 and 60 months post-partum.

Results Compared with the control, all three treatments had a
significant impact at 4.5 months on maternal mood (Edinburgh Postnatal
Depression Scale, EPDS). Only psychodynamic therapy produced a rate of
reduction in depression (Structured Clinical Interview for DSM—III
— R) significantly superior to that of the control. The benefit of
treatment was no longer apparent by 9 months post-partum. Treatment did not
reduce subsequent episodes of post-partum depression.

Conclusions Psychological intervention for post-partum depression
improves maternal mood (EPDS) in the short term. However, this benefit is not
superior to spontaneous remission in the long term.

Post-partum depression occurs following approximately 10% of deliveries
(
Cooper et al, 1988;
Cox et al, 1993;
O'Hara & Swain, 1996).
Although the disorder tends to remit spontaneously after 4-6 months
(
O'Hara, 1997), it causes
considerable distress and disruption to the women and their families
(
O'Hara, 1997), and the
delivery of effective treatment is considered a priority. Well-controlled
research trials have revealed that post-partum depression reponds to treatment
in the short term (
Holden et al,
1989;
Wickberg & Hwang,
1996;
Appleby et al,
1997;
O'Hara et al,
2000), with treatment roughly doubling the spontaneous recovery
rate. However, it is unclear whether this short-term effect is maintained and
it is not clear whether different forms of psychological intervention might
have different impacts. In order to address these questions, a controlled
treatment trial was conducted in which three forms of brief psychological
intervention, delivered to a community sample of women with post-partum
depression, were compared with routine primary care, and the women were
followed up on four occasions until 5 years post-partum.

METHOD

Source of sample

A large consecutive series of primiparous women (i.e. 3222), identified
through the birth records of Addenbrooke's Hospital, Cambridge, was screened
between January 1990 and August 1992 for mood disturbance in the early
post-partum period by means of a postal administration of the Edinburgh
Postnatal Depression Scale (EPDS;
Cox
et al, 1987). Those with suspected post-partum depression
(EPDS score of 12 or more) were assessed systematically and those found to be
suffering from post-partum depression were invited to take part in a study in
which ‘different forms of help to mothers’ were being
compared.

Inclusion/exclusion criteria

Women were considered eligible for the study if they fulfilled the
following criteria: primiparous, living within a 15-mile radius of the
maternity hospital and with English as their first language. Women were
excluded if they had delivered prematurely (before 36 weeks' gestation), if
their infant had any gross congenital abnormality, if they had not had a
singleton birth or if they were intending to move out of the area within the
period of the intervention.

Treatment groups

The women were assigned to one of four conditions.

Routine primary care, involving the normal care provided by the primary
health care team (i.e. general practitioners and health visitors) with no
additional input (apart from assessment) from the research team. This is the
control condition of the trial.

Cognitive—behavioural therapy (CBT), in which a range of techniques
(
Hawton et al, 1989)
was used in the context of an appropriately modified form of the interaction
guidance treatment described by McDonough
(
1993). The treatment was
primarily directed not at the maternal depression itself but at problems
identified by the mother in the management of her infant (concerning, for
example, feeding or sleeping), as well as at observed problems in the quality
of the mother—infant interaction. In the context of a supportive
therapeutic relationship, the mother was provided with advice about managing
particular infant problems, was helped to solve such problems in a systematic
way, was encouraged to examine her patterns of thinking about her infant and
herself as a mother, and was helped through modelling and reinforcement to
alter aspects of her interactional style.

Psychodynamic therapy using the treatment techniques described by Cramer
& Stern (
Cramer et al,
1990;
Stern,
1995), in which an understanding of the mother's representation of
her infant and her relationship with her infant was promoted by exploring
aspects of the mother's own early attachment history.

Non-directive counselling, replicating the treatment provided in the
Edinburgh study by Holden et al
(
1989), in which women were
provided with the opportunity to air their feelings about any current
concerns, such as marital problems or financial difficulties, as well as
concerns they might raise about their infant.

The three active intervention arms of the trial were selected to determine
whether treatments that focused (in different ways) on the mother—infant
relationship would be more advantageous than a non-specific treatment already
established as being effective in alleviating low maternal mood.

Therapy was conducted in the women's own homes on a weekly basis from 8
weeks to 18 weeks post-partum. This is the same timing as the treatment
delivered by Holden et al
(
1989), and the 8-week
invitation reflects the time when post-natal depression is likely to be
detected by the primary care team in the course of routine post-natal
contacts.

Method of allocation

The women were allocated randomly to a treatment group by the study
recruiter, who drew one of four coloured balls from a bag, the assignment of
each therapy to a different coloured ball having been defined at the start of
the study and maintained until the end of the recruitment period.

Therapists

There were six study therapists: a specialist in each of the three research
treatments and three non-specialists (including two seconded National Health
Service health visitors) who were trained in two of the treatments, which
allowed for an examination of expertise effects. P.J.C. and L.M. ran weekly
supervision sessions with the therapists, during which the progress of each
case was reviewed and adherence to the treatment protocols was ensured.

Assessments

Mental state assessments were made at baseline (immediately after
treatment), at 9 and 18 months post-partum and at 5 years, by a trained
assessor unaware of the treatment group to which the women had been assigned.
Maternal mood was assessed using the EPDS as a self-report measure, as well as
by interview using the depression section of the Structured Clinical Interview
for DSM—III—R (SCID;
Spitzer
et al, 1989). The content of therapy was assessed, to
check for therapist adherence, using 30 items from the Therapist Rating Scale
(
Silove et al, 1990).
Assessments also were made of the children's cognitive and emotional
development and of the quality of the mother—infant relationship (see
Murray et al, 2003,
this issue). The first three waves of assessments were made in the women's own
homes, and the fourth and fifth assessment (i.e. 18 months and 5 years
post-partum) were carried out in the research unit.

Data analysis

A power analysis, based on the findings of Holden et al
(
1989) that 69% of women with
post-partum depression who received counselling remitted compared with 37% of
controls, indicated that subsamples of 44 would be sufficient to detect a
treatment effect on rates of depressive order (5% significance level, 80%
power).

Initially, the sub-scales of the questionnaire concerned with therapy
adherence were analysed to establish whether they differed between the
treatment groups. The distributions of the sub-scale measures were compared
using the Kruskal—Wallis one-way analysis by ranks, and the differences
between the treatments were calculated using the Hodges—Lehmann
estimator. Pairwise comparisons, adjusted appropriately, were used to
establish significant differences (
Siegel
& Castellan, 1988). Linear and logistic random effects models
were used to analyse the repeated measures of maternal mood
(
Goldstein, 1995;
Diggle et al, 1996;
Everitt & Pickles, 1999).
These models allow for the effect of the different therapies on maternal mood
over time to be investigated, while taking account of the correlation between
the repeated measures, and they also allow for covariates of interest to be
controlled for. In the models, the time of each assessment visit was treated
as a discrete variable.

Initially, only the baseline EPDS scores were controlled for. Further
models were then fitted to explore the effect of treatment over time, after
controlling for social adversity (which was thought to be unbalanced between
the treatment groups and related to maternal mood) and other baseline
covariates. Several other factors thought to influence maternal mood were
investigated, including infant gender and maternal age (under 25 years defined
as young) and education level (up to ‘O’ level or GCSE defined as
low). In addition, two derived background variables — negative
orientation to motherhood and social adversity — were investigated, as
suggested by previous research (
Murray
et al, 1996). These were derived from factors assessed
antenatally (i.e. the former from previous termination of pregnancy, an
unplanned pregnancy, poor relationship with own mother and inability to
confide with own mother; the latter from low income, poor housing and being
single or divorced).

Covariates were retained in the model if they reached a significance of
P < 0.05. The adjusted odds ratios from the logistic regression
models were converted to approximate relative risks using the method of Zhang
& Yu (
1998), because the
rates of depression were common (i.e. > 10%;
Davies et al, 1998).
Two subgroup analyses were performed: a completer analysis and an analysis to
investigate the effect of level of expertise. The random effects models were
fitted using Mlwin for Windows (Institute of Education, London, UK). All other
analyses were performed using the SAS program package for Windows (version
8.02, SAS Institute, Cary, NC).

RESULTS

Description of sample

A total of 206 women were identified who fulfilled DSM—III—R
(
American Psychiatric Association,
1987) criteria for current major depressive disorder. Of these,
only 13 refused to take part in the study. As can be seen from the CONSORT
diagram (
Fig. 1), the remaining
193 women were assigned randomly to one of four conditions. Three women
refused to participate in the study after being informed of their therapy
group (one assigned to CBT and two to psychodynamic therapy). Nineteen women
dropped out of treatment early (i.e. they had four or fewer sessions) or moved
away from the study area. Of the women identified as being eligible for the
study, 171 (83%) completed therapy: 42 in the non-directive counselling group,
41 in the CBT group, 40 in the psychodynamic therapy group and 48 in the
control group. All of the 190 women successfully assigned to one of the four
study conditions were approached for follow-up assessments at 4.5, 9 and 18
months. At 5 years, in addition to all the control participants, only those
women who had completed therapy were approached. At 4.5 months, 89% of the
women successfully assigned to a treatment condition were assessed, at 9
months this figure was 95%, at 18 months it was 94% and at 5 years it was 73%
(71% of all controls and 81% of those who completed therapy were assessed at 5
years).

Demographic features

Table 1 contains demographic
information on those in the control and the treatment groups. The four groups
were comparable on all the background demographic factors. They were
comparable also in terms of one of the antenatal indices of interest —
negative orientation to motherhood. However, there appeared to be a difference
between the groups in terms of the second antenatal index of interest —
marked social adversity — with more women experiencing high adversity in
the control group (i.e. 35%) and fewer women in the psychodynamic therapy
group (i.e. 10%).

Demographic characteristics of the women successfully assigned to one
of the four conditions

Ten per cent of the women who were successfully randomly assigned did not
complete the trial (6 from the non-directive counselling group, 1 from CBT, 8
from psychodynamic therapy and 4 from the control group). Women were
considered to be completers if they attended more than four treatment sessions
(for women assigned to treatment) and did not move out of the study area
during the therapy period. No difference was found between the completers and
non-completers on the measures of maternal mood collected pre-therapy and at
4.5, 9 and 18 months. The women who did not complete therapy were younger
(mean=24 years, s.d.=6.3) than those who did complete (mean=28 years,
s.d.=5.1; t=-2.9, d.f.=186, P=0.004). The non-completer
group also had a higher proportion of women who were single or separated
(Fisher's exact test P=0.05). The two groups were comparable in terms
of level of education and the two derived background measures of orientation
to motherhood and social adversity.

Therapy adherence

In order to confirm that the three treatments were being delivered as
intended, the Therapist Rating Scale was administered to the women who had
received one of the three index treatments. The responses to this
questionnaire are summarised in
Table
2, along with the median differences between treatment groups. The
Kruskal—Wallis (KW) test was used to establish whether the responses to
each of the six sub-scales differed between the treatment groups. A treatment
effect was found for four of the sub-scales: cognitive focus (KW=24, d.f.=2,
P<0.001), behavioural tasks (KW=58, d.f.=2, P<0.001),
organisation (KW=28, d.f.=2, P<0.001) and relationship (KW=41,
d.f.=2, P<0.001). Pairwise comparisons, adjusted appropriately,
revealed that the women who had been assigned to the CBT group had
significantly higher median responses for cognitive focus, behavioural tasks
and organisation compared with the women assigned to the non-directive
counselling and psychodynamic therapy groups. The women who received
psychodynamic therapy had a significantly higher median response on the
relationship sub-scale compared with the women assigned to the non-directive
counselling and the CBT groups. The inner conflict and transference sub-scales
did not differ between the treatment groups.

This pattern of findings confirms that the treatments were delivered as
intended.

Impact of treatment on maternal mood

The Edinburgh Postnatal Depression Scale

The EPDS scores after the treatment period are summarised in
Table 3 for all women who were
randomised successfully. At 4.5 months, compared with the women in the control
condition, the group of women who had received any one of the three treatments
had lower EPDS scores (mean difference was -1.9; 95% CI -3.5 to -0.3). After
4.5 months the mean EPDS scores were similar. At 9 months the mean difference
was 0.1 (95% CI -1.7 to 1.9), at 18 months it was 0.3 (95% CI -1.4 to 2.1) at
5 years it was -0.7 (95% CI -2.8 to 1.4).

From
Fig. 2a, which shows
the mean EPDS score by treatment condition and assessment visit, it can be
seen that the mean EPDS scores were lower after the therapy period for all
four groups. At 4.5 months post-partum, the women in the control group appear,
from
Fig. 2a, to have had a
smaller decrease on average in their EPDS score than the women in the three
therapy groups. This is supported by
Fig.
2b, which shows that the mean percentage reduction in EPDS from
baseline is much lower for the control group at 4.5 months compared with all
the treatment groups. However, at 9 months post-partum, treatment appears to
have produced no further reduction in the mean EPDS scores.

The random effects model for the repeatedly measured EPDS scores confirms
these initial observations. At 4.5 months, after controlling for baseline
EPDS, the EPDS scores were found to be significantly lower for all three
treatment groups compared with the control group (see
Table 3). After the 4.5-month
assessment, all treatment groups were found to be comparable with the control
condition.

After controlling for social adversity and level of education, the same
magnitudes of effects were found.

An analysis of only the women who had successfully completed therapy
produced the same findings.

Results on the Structured Clinical Interview for
DSM—III—R

At 4.5 months, 40% of the controls had remitted from depression (see
Table 4). In comparison, of the
135 women who had received treatment, 61% had remitted at this time
(percentage difference of 21%; 95% CI 5 to 37%). After 4.5 months the levels
of remission were similar for the treated and control groups. At 9 months only
4% more of the women in the treated group had remitted compared with the
control group (95% CI -11 to 19%), at 18 months 11% less of the treated group
had remitted (95% CI -25 to 3%) and at 5 years 4% more of the treated women
had remitted (95% CI -11 to 21%).

The repeated post-partum SCID measures of depression were analysed using a
random effects logistic model. After controlling for baseline EPDS, at 4.5
months, compared with the controls, there was no difference in the rate of
depression for the women in the non-directive therapy and the CBT groups.
Compared with the control condition, psychodynamic therapy was found to be
more effective in reducing the rate of depression (see
Table 4). After the 4.5-month
assessment, the three treatment groups were found to be not significantly
different from the control condition with respect to reducing the risk of
post-natal depression.

The effects of treatment remained the same after controlling for social
adversity and level of maternal education.

An analysis of the outcomes of the women who had successfully completed
therapy produced the same findings as those above.

Expertise effects

For women who received treatment, an expertise effect was found for
maternal mood at both 4.5 months and 9 months, after controlling for type of
treatment, baseline EPDS, social adversity and level of education. A
significantly greater reduction in EPDS score was found for women treated by
non-specialists compared with those treated by specialists at 4.5 months
(-2.1; 95% CI -3.7 to -0.5, P=0.01) and at 9 months (-2.0, 95% CI
-4.0 to -0.1; P=0.04). In order to investigate further the effect of
the therapists' level of expertise in relation to the control condition, six
treatment categories were created: a specialist and a non-specialist group of
each of the three treatments. After controlling for baseline EPDS, social
adversity and level of education, all three non-specialist treatment groups
were found to be significantly different from the control condition in terms
of EPDS score at 4.5 months. Treatment effects at 4.5 months were estimated as
-2.2 for non-specialist non-directive counselling (95% CI -4.0 to -0.3;
P=0.02), -3.3 for non-specialist psychodynamic therapy (95% CI -5.4
to -1.1; P=0.003) and -2.4 for non-specialist CBT (95% CI -4.1 to
-0.8; P=0.003). After 4.5 months there was found to be no significant
difference between the control condition and each of the non-specialist
groups. At all assessments, and for all three treatments, women treated by
specialists were no different from those in the control group.

For women who had received treatment, level of expertise was found to be
unrelated to recovery from depressive disorder, after having controlled for
type of treatment, baseline EPDS, social adversity and level of education.

Subsequent post-partum depression

Of the 138 women assessed at 5 years post-partum, a total of 98 had had a
subsequent delivery. At the 5-year assessment, when detailed psychiatric
histories were taken, note was taken of whether any episode of depression
occurred in the period immediately following subsequent deliveries. There were
27 episodes of post-partum depression subsequent to the initial episode: 20 of
these occurred in women who had received treatment (i.e. 28%) and 7 occurred
in women who had received no intervention (i.e. 27%). There was no difference
between these rates (percentage difference of 1%; 95% CI -19% to 20%,
χ2=0.01; d.f.=1). Treatment for the initial episode of
post-partum depression, therefore, did not have an impact on the risk of
subsequent post-partum depression.

DISCUSSION

Treatments for post-partum depression

There have been a number of studies of both the pharmacological and
psychological treatment of post-partum depression. Only one of these has been
a formal trial of an antidepressant medication. Appleby et al
(
1997), in a factorial design
involving the use of fluoxetine or placebo in combination with one or six
counselling sessions, demonstrated an impressive antidepressant effect for
both the active drug and the psychological treatment over a 3-month treatment
period. However, there was no additive effect of the two treatments, and drug
treatment was not superior to the psychological treatment. Given that, of the
women with depression invited to take part in the study, less than half agreed
and the main reason for refusal was ‘reluctance to take
medication’, the role of fluoxetine, or indeed any other antidepressant
medication, in the treatment of post-partum depression is likely to be
limited.

In another placebo-controlled trial of a pharmacological agent
(
Henderson et al,
1991), treatment with oestradiol skin patches for 2 months was
found to produce a greater elevation in mood than placebo; but because the
patients in this study were all medical referrals, they are likely to have
been a sample selected for a greater severity of depression than is typical of
the population of women with post-partum depression. The extent to which the
findings from this study can be generalised must, therefore, be
questioned.

In contrast to the questionable clinical utility of antidepressant and
hormonal treatments, several studies have found psychological forms of
treatment, notably counselling, to be both highly acceptable to the women and
highly effective. Thus, Holden et al
(
1989), in an early study of
brief non-directive counselling delivered women with post-partum depression by
health visitors, found the rate of recovery after 13 weeks to be twice that
among those who received counselling compared with those who did not. Similar
findings have been reported from a study carried out in Sweden, where child
health clinic nurses delivered counselling to women with post-natal depression
women (
Wickberg & Hwang,
1996).

There has been surprisingly little research interest in the application of
psychological forms of treatment other than counselling in post-natal
depression. Stuart & O'Hara
(
1995) have advocated the use
of interpersonal psychotherapy. A recent controlled trial in which
interprersonal psychotherapy was compared with a waiting-list control group
found a significant benefit of the index treatment in terms of maternal mood
and social functioning (
O'Hara et
al, 2000). Its efficacy compared with other forms of
treatment such as CBT or counselling is not known. Its effectiveness as a
treatment delivered within the health service also is not established.

Individual v. group treatment

In the current study, the offer of psychological intervention was highly
acceptable to the women identified as being eligible to join the study.
Indeed, very few of those offered one of the interventions refused to enter
the trial, and few of those who accepted the offer of treatment dropped out.
This stands in marked contrast not only to take-up rates for studies that have
offered pharmacological treatment as a component of the study
(
Appleby et al, 1997)
but also to studies in which group interventions have been offered in
pregnancy and the early post-partum weeks to be vulnerable women and women
with depression (
Stamp et al,
1995;
Buist et al,
1999;
Brugha et al,
2000;
Elliott et al,
2000). In fact, mothers with post-partum depression are commonly
reluctant to make use of group-based mother and baby clinics run by health
visitors (
Seeley et al,
1996). Thus, although group-based interventions may be useful in
certain sub-samples of women, it seems likely that for the majority of
primiparous women with post-partum depression initial support needs to be
offered on a one-to-one basis.

Findings of the current study at 4.5 months post-partum

After having controlled for baseline EPDS scores, the EPDS scores at 4.5
months were found to be lower for all three treatment groups compared with the
control condition. Indeed, by 4.5 months the women in all three treatment
conditions had experienced a marked reduction in depressive symptoms. The lack
of a significant difference in terms of remission from depressive disorder
between two of the treatment conditions and the controls requires some
explanation. First, the rate of recovery of those in the control condition was
somewhat higher than that reported in previous studies (e.g.
Holden et al, 1989;
Wickberg & Hwang, 1996).
This could be attributable to the amount of attention they received in both
the recruitment and assessment process. Second, the outcome of those who
received non-directive counselling and CBT from a specialist was unexpectedly
poor. Indeed, if only the findings from the health visitors is considered for
both the non-directive counselling and the CBT conditions, the remission rate
for non-directive counselling (which was 54% for all therapists) was 60%, and
the remission rate for CBT (which was 57% for all therapists) was 66%. The
likely explanation for this is that the health visitors were the only
therapists within the trial who had previous experience of home visiting.

Findings of the current study at 9 months post-partum

By 9 months post-partum the positive benefit of the treatments was no
longer apparent, because the spontaneous remission rate brought the women in
the control group to the same point as those in the three treatment groups.
Indeed, apart from the significant difference immediately following the
intervention between the women who had received the treatments and those who
had not, there were no differences in terms of subsequent depression between
the controls and the index groups at either 9 or 18 months. At 5 years (when
only those who completed treatment or had been assigned to the control
condition were approached for assessment) there was still no benefit of having
received the intervention. Thus, none of the treatments was related to the
number of subsequent depressive episodes, post-partum or otherwise.

Clinical Implications and Limitations

CLINICAL IMPLICATIONS

Such interventions also bring about short-term improvement in some
aspects of the early mother—infant relationship and child
outcomes.

Health visitors are effective in delivering home-based intervention to
women in the post-partum period, and their training and practice should be
extended to encompass the detection and management of mothers with postnatal
depression.

LIMITATIONS

The sample was one that was generally at low risk, and comprised only
primiparous mothers; the generalisability of the findings to high-risk and
multiparous populations is uncertain.

The sample was underpowered to detect differences between the treatment
groups.

Although the efficacy of the interventions has been demonstrated for
some outcomes, effectiveness studies are required to establish whether such
benefits would be obtained in routine practice.

Acknowledgments

We are indebted to all the women and children who took part in this study.
This research was carried out within the Cambridge University Department of
Psychiatry. The initial trial was supported by a grant from Birthright. The
5-year follow-up was supported by the Medical Research Council. We are
grateful to Angela Cameron, Sian Coker, Jenny Corrigal, Bridget Halnan,
Sheelah Seeley and Claire Wilson for their help with carrying out the
treatment, to Jill Butler, Janet Edwards, Alison Hipwell and Agnese
Fiori-Cowley for their help with the assessments and to Matt Woolgar for his
comments on the manuscript.